1. Field of the Invention
The present invention relates to the field of portable electronic devices such as personal digital assistants or palmtop computer systems. Specifically, the present invention relates to an apparatus and method for utilizing an optical sensor based user interface for registering user input.
2. Related Art
Portable computer systems, such as “palmtop” computer systems, or personal digital assistants (PDA) have become commonplace and extraordinarily useful electronic devices. A palmtop computer system includes a hand-held device and a cradle device to which it ports and which connects and synchronizes it to other computers. Owing to their portability, capability, and versatility, hand-held computer devices are designed to be used in a wide variety of environments, for many applications.
Portable computers are usually robustly packaged devices, designed for simplicity of operation and durability. Few penetrations expose their interiors, wherein their operational components reside. However, function/field selection buttons, on/off, interconnection, and other switching components expose the interior to some degree to allow accessibility for switching and other operations. Mechanical switching components, such as switches, buttons, and, especially, thumbwheels and associated potentiometers, variable capacitors, and the like, while ostensibly durable, have definite physical vulnerabilities and finite operational lifespans. Further, although designed for operational simplicity, using a portable computer system by manipulating these switching components requires some degree of tactile skill.
Portable computer systems may be used in harsh environments, unlike other computers designed with less of a degree of mobility, such as desktop computer systems. For example, desktop computer systems most often find application in offices, classrooms, and similar milieus, with environments subject to some relatively satisfactory degree of control. Portable computer systems, on the other hand, while indeed they may also be used in such environments, are designed for use almost anywhere, contributing to their versatility and usefulness, e.g., a vehicle, outside, etc.
Portable computer systems are frequently and reliably deployed in-transit, in private and public modes of transportation of almost every kind. Portable computer systems find operational deployment in the field in, for example, industrial, urban, marine, construction, and even military application. Under these circumstances, their operational environment may vary widely and change rapidly, often subject to little or no control. These environments may also be quite rugged, extreme, wet, dirty, contaminated, and dusty.
When their operational environment is rugged, extreme, wet, dirty, dusty, or contaminated, operation of the portable computer system may contribute to or cause internal contamination or physical damage. Environmental contaminants such as moisture, dirt, dust, chemicals, and the like, may penetrate even the small openings for exposure of switching components to user manipulation, especially thumbwheels and their associated potentiometers. Once inside the portable computer, or a connector or button, they may cause fouling, damage, or destruction of is internal microelectronic and other components. And while switching components may be designed for durability, they all display some degree of physical vulnerability and aging degradation characteristics.
Although designed for operational simplicity, portable computer systems require some dexterity to operate properly. To operate the portable computer system to accomplish these tasks, controls and switching components must be manipulated. Manipulation enables, for example, choosing a screen, scrolling through various screens, selecting an on-screen icon, field, menu, listing, or data entry, or “writing to” or “typing on” an on-board touch-sensitive writing pad-like surface with a stylus, or other touch-enabling probe.
However, also owing to their versatility and portability, portable computer systems may be operated by a user who is purposefully multi-tasking, or otherwise engaged in other activities besides operating the portable computer. Portable computer systems are routinely utilized to, for example, access telephone numbers from an on-board telephone list, reminders from an on-board list of memoranda, gaming, portable internet browsing or email access, and a host of other computer-enabled and/or enhanced activities, all while the user is fully engaged in some other task.
When the circumstances under which portable computer systems are used become complex and distracting, operation of the portable computer system may become difficult. This may detract from the computing experience of the user. It may cause errors or loss of data, and/or require operational steps to be repeated. This is inconvenient and costly.
Conventionally, an approach to solving the problem of internal exposure of portable computers to environmental contaminants has been to attempt to minimize the interior exposure. This has been accomplished in one attempted solution by reducing the number and size of penetrations through their cases, and to seal the penetrations. Reducing the number of penetrations requires a concomitant reduction in the number of switching components. This requires switching components to have multiple, selectable functions. However, this has the undesirable effect of increasing operational complexity. Sealing the penetrations increases packaging complexity and increases unit costs, and interferes with switching component operations.
Conventionally, an approach to solving the problem of making portable computer device operation less complicated for engaged users, especially those simultaneously engaged in activities besides computing, has been to simplify the computer-user interface. This has been attempted, in one approach, by adding switching components. However, this has the undesirable effect of increasing package penetration with resulting increased internal exposure of the computer device to environmental contaminants.
Another conventional method of attempting to solve this problem has been to change the characteristics of the switching components. For instance, in one approach, a “jog wheel,” “thumb wheel,” or similar of rotary dial-type mechanism. However, this particular approach is especially vulnerable to environmental contamination problems.
Rotary dial-type mechanisms rotate about a shaft, which penetrates the package of the portable computer system to actuate the rotationally variable electrical components contained within. This shaft penetration is potentially a route for incursion of environmental contamination to the sensitive interior of the portable computer device. Exacerbating this problem is the size of the rotary dial, itself. Normally, such dials are larger than other switches penetrating the portable computer device package. Further, the dial has a lower surface facing the portable computer device package, yet not quite abutting it.
The space beneath the dial, between the dial and the portable computer device package is especially susceptible to the accumulation of moisture, detritus, dirt, dust, debris, oil, and chemicals. This is particularly problematic for three reasons. First, because the potential environmental contaminants remain there, proximate to a potential incursion route to the portable computer system interior even after the portable computer system is removed from the contaminating environment. Second, it increases the time of exposure to the potential environmental contaminants, thus increasing the probability of incursion. Third, the space between the dial and the portable computer device package is very hard to clean, and attempts to clean it may actually force contaminants into the shaft incursion route and into the interior of the portable computer.
The conventional art is problematic therefore for two related reasons. First, because attempts to promote ease of use of portable computer devices threaten increased risk of internal exposure thereof to environmental contamination. Second, because attempts to reduce risk of internal exposure of portable computer devices to environmental contamination complicate their use and increase their cost.
What is needed is a method and/or apparatus that promotes a positive computing experience for users of portable computer systems and/or increases overall durability and/or longevity thereof. What is also needed is a method and/or apparatus that promotes the operational simplicity of portable computer systems. Further, what is needed is a method and/or apparatus that enables efficient portable computer function, field, and data selection, gaming, input, interconnection, and other switching-related functions without exposing the portable computer interior to any degree to incursion of environmental contamination. Further still, what is needed is a method and/or apparatus that achieves the foregoing accomplishments while allowing the full range of both portability and environmental exposure, and range and ease of use characteristic of portable computer devices, yet without complete redesign.